What will be the ratio of milk and water in the mixture formed by mixing milk and water that are pre...........

Explanation:

Let us suppose V1, V2 and V3 are the volumes respectively of the vessels in which milk to water ratios are 4:3, 5:2 and 3:2.
Total milk = 4*V1/7 + 5*V2/7 + 3*V3/5
= (20*V1 + 25*V2 + 21*V3)/35
Total water = 3*V1/7 +2*V2/7 + 2*V3/5
= (15*V1 + 10*V2 + 14*V3)/35
Milk :Water = (20*V1 + 25* V2 + 21*V3)/(15*V1 + 10*V2 + 14*V3)
Knowing V1, V2 and V3 we can calculate the milk:water ratio.
In the special case V1 = V2 = V3,
Milk:Water = 66:39 = 22:13.